A GSM (group special modem/global system for mobile communication) system is known as one of digital cellular systems for cellular phone. In this GMS system, an IC card (SIM card) is used as a subscriber identity module (SIM). In this case, it is necessary for the cellular phone to be equipped with a small and detachable card holder.
On the other hand, a service for obtaining data from a Web server on the Internet by using a cellular phone has started. In some cases, a memory card is used to store the data obtained and to use the data in other electronic appliance. Also in the cases, it is necessary for the cellular phone to be equipped with a small and detachable card holder.
In order to use both SIM card and memory card on a cellular phone, the cellular phone must be equipped with two card holders for the SIM card and memory card.
To attain the ultimate portability, the cellular phone employs a mounting board as small as possible, whose degree of integration is maximized. However, since the card holder has such a size as to accommodate the IC card, it occupies a quite larger space than that of other parts mounted on the mounting board of the cellular phone.
As mentioned above, in order to mount two card holders on the cellular phone, the two card holders must be mounted on the mounting board. This prevents the mounting board of cellular phone from being downsized.
Thus, hitherto, if attempted to use both SIM card and memory card on the cellular phone, the cellular phone must increase in size, which does not meet the request for reducing the size of cellular phone.